Washing and cleaning agents and/or cosmetic agents usually contain scents that impart a pleasant and fresh odor to the agents. The scents usually mask the inherent scent note of the other ingredients, producing a positive odor impression in the consumer. In the sector of washing agents, scents are particularly important constituents of the composition, since the laundry should have a pleasant and fresh smell both when wet and when dry. A fundamental problem in the utilization of scents consists in the fact that these substances are volatile substances, since otherwise a scent effect could not be achieved. The problem faced when using scents, for example, in washing and cleaning agents, and also for use in cosmetic agents, is thus that despite the volatility of the compounds, it is desirable to produce a long-lasting scent effect that is as consistent as possible. In addition, the scent impression of a perfume changes over time, since the fragrances that represent the fresh and light notes of the perfume volatilize more quickly, because of their high vapor pressure, than the scents which represent the middle and base notes.
One approach to solving this problem involves applying scents onto carrier materials and coating the scented carriers, or encapsulating scents or incorporating them into compounds (for example, cyclodextrin-perfume complexes). A further possibility that exists is to bond the scents chemically to carrier media, the chemical bond being slowly broken and the scent released as a result. This kind of carrier-bound precursor form of a scent is also known as a “pro-fragrance” or scent storage substance. In this connection, International Patent Application WO 2007/087977 discloses the use of 1-aza-3,7-dioxabicyclo[3.3.0]octane compounds as scent storage substances for delayed release of scent aldehydes and scent ketones by hydrolysis. An alternative possibility for delayed release of scents is represented by the use of so-called photoactivatable substances as scent storage substances. The action of sunlight or another electromagnetic radiation source of a specific wavelength induces breakage of a covalent bond in the scent storage substance molecule, thereby releasing a scent. For effective release of the scent, the above-described process must tolerate the presence of oxygen and water.
In this connection, U.S. Pat. No. 6,949,680 discloses the use of specific phenyl ketones or pyridyl ketones as photoactivatable substances that, in a photochemical fragmentation, release a terminal alkene as an active substance in the presence of light. The aforesaid active substance possesses, for example, a scent-imparting or antimicrobial activity that is first delayed by the photochemically induced decomposition, and over a longer period of time is released on a specific surface. The aforesaid photolabile phenyl ketones or pyridyl ketones constituting scent storage substances are manufactured in a complex, multi-step synthesis method using protecting-group operations; the synthesis must be individually adapted for each individual active substance. WO 2009/118219 A1 describes, as scent storage substances, photoactivatable substances that permit delayed release of cyclic alkenes having a so-called semicyclic double bond.
Accordingly, it is desirable to make available photoactivatable substances, constituting scent storage substances, that permit the delayed release of cyclic compounds having at least one cyclic double bond, in particular of cyclic terpenes or cyclic terpenoids having at least one cyclic double bond. In addition, it is desirable to make available a simple and economical synthesis method for manufacturing the aforesaid scent storage substances.
In view of this, desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.